Milk snakes (Lampropeltis triangulum) are very popular and common snakes. They can be found from Canada all the way down to Venezuela. If you are considering one for a pet, you likely have an important question: how long do milk snakes live?
Milk snakes can live over 20 years in captivity.
In the Wild
The lifespan in the wild isn’t well-studied. These animals can reproduce after about 4 years. Most estimates for the wild lifespan place it around 14-16 years.
This is partly because of factors like predators and illness. Animals in captivity have access to veterinary care, steady food, and protection from the elements and predators. A wild snake has to survive predators, bad weather, prey availability, and even other milk snakes.
Threats to Milk Snakes
Milk snakes are common prey for many mammals and birds. Young snakes are common prey for animals like bullfrogs and birds. Older snakes are frequent prey for larger mammals like coyotes and raccoons.
The exact predators depend on the area. Most milk snakes rely on Batesian mimicry to avoid predators. The banded appearance of many subspecies of milk snake mimics the look of the deadly coral snake.
While humans can easily tell the difference in patterning, most animals cannot.
Many bird species have a natural aversion to aposematic signaling. This is signaling that warns predators that an animal is toxic, whether from venom or poison.
These snakes also mimic rattlesnakes that may share their range.
These animals mimic both with patterning and behavior. Milk snakes that want to warn off potential predators will rattle their tail in leaves or similar debris. This makes it sound like a predator has come across a rattlesnake and the predator is likely to flee rather than risk a bite.
However, Batesian mimicry is most useful in areas where the model is found. In its absence, Pfennig et al. 2007 found that this mimicry can increase predation.
It also pits the naked at risk of being killed by humans who believe it may be a venomous species.
Illnesses are another risk for wild snakes. A prey animal may fight back and leave injuries. These can become infected and eventually kill the snake.
Respiratory illnesses are a big killer for snakes. Having a respiratory illness makes it harder for the snake to breathe and can kill them. Some parasites also will kill a snake host.
One common parasite hardens the stomach and makes it difficult for the snake to eat. This will prove fatal. Other factors like poor weather and climate can kill snakes.
Since they are ectotherms they rely on outside temperature to regulate their body temperature. If there is a sudden heat wave or cold snap, this can kill them. Lack of prey can also kill snakes. If the snake can’t find a meal for a long time, it will weaken to the point it can’t hunt anymore.
Encounters with humans are a major danger for snakes. Humans can mistake a snake for a dangerous one and may kill it. Snakes that are crossing a road can also be killed by dogs.
Domesticated animals like dogs and cats can prey on milk snakes. In areas where these animals are allowed to roam or have large feral populations, you will see more snakes lost to predation.
Human construction can also damage milk snake habitat. Besides risk from increased traffic, snakes may lose important habitat including safe incubation places for their eggs.
While milk snakes will enter buildings looking for prey, this puts them at risk from the occupants.
Everything you need to know about caring for Milk Snakes in captivity:
Read our Milk Snake Care Sheet (Complete Guide)
Milk snakes have been known to live for over 20 years in captivity.
The oldest recorded individual was a wild-caught specimen that was already an adult.
Most animals recorded as being wild caught seem to live around 16-20 years in captivity. Since the data at the source stopped being collected in the 90s, there is not much about captive-bred lifespan for any subspecies.
Captive-bred animals are noted as being healthier and more docile in general. They also seem to experience less stress from humans since they learn from a young age that humans aren’t a threat.
A wild-caught snake will feel like you are a predator for longer on average. This means the animal will experience more stress in the long term. Stress lowers the immune system and can kill a snake.
Generally, poor care and inattention kills captive snakes. A poor temperature range will kill a snake since it can’t thermoregulate properly.
This makes it difficult for the snake to digest its food if the temperature is too low. If it is too hot, the snake can suffer from heat stroke and die. Snakes also need access to water since they need to stay hydrated.
Illness that isn’t caught in time can kill a snake.
Any changes to the skin or breathing of the animal should be checked out. Poor shedding can cause injuries and infection, as well feeding live prey if it fights back.
Parasites are also frequently fatal. You need to practice good hygiene and be careful about where you source the prey for your snake.
Cancer is another killer. Good vet care is essential for a milk snake to live a long and healthy life.
Milk snakes can live for over 20 years in captivity. In the wild, this is likely shorter. If you take good care of a snake, it will likely be with you for decades. If you have any questions or comments, leave them below!